Program isn't working properly

[stdq]

My C program isn't reaching the "return 0;" statement:

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
 
char *invertString( const char *const str );
 
int main( void )
{
    char string[ 25 ];
    char *ptr;
 
    printf( "Enter a string without whitespace: " );
    scanf( "%25s", string );
 
    ptr = invertString( string );
 
    if ( ptr != NULL )
    {
        printf( "The inverted string is %s.\n", ptr );
    }
    else
    {
        printf( "A memory error occurred.\n" );
    }
 
    printf( "LINE %d.\n", __LINE__ );
 
    return 0;
}
 
char *invertString( const char *const str )
{
    unsigned int i;
    unsigned int j;
    unsigned int lengthOfStr = strlen( str );
    char *newStr = ( char * )malloc( ( lengthOfStr + 1 ) * sizeof( char ) );
 
    if ( newStr == NULL )
    {
        printf( "ERROR!" );
        return newStr;
    }
 
    for ( i = lengthOfStr - 1, j = 0 ; i >= 0 ; --i, ++j )
    {
        *( newStr + j ) = *( str + i );
    }
 
    *( newStr + j ) = '\0';
 
    return newStr;
}

The program is supposed to invert a string by creating a new string and there putting the contents of the original string in reverse order. The problem is, it isn't reaching the "return 0;" statement. I even added the statement

printf( "ERROR!" );

inside the invertString function to check whether a memory error is occurring, but it isn't executing. What is possibly going on? Thanks in advance.

PS: the encoding of the source file is CP1252.
PS: the program is compiling successfully.

[weaknessforcats]

Your invertString function is not returning.

for ( i = lengthOfStr - 1, j = 0 ; i >= 0 ; --i, ++j )

When i gets to zero it still satisfies the condition to continue the loop, which causes i to become -1. And off you go on an infinite loop.

[stdq]

Thanks for your answer. But when I ran the program, its execution ended automatically.

[weaknessforcats]

The code you posted does not work. It crashes in an infinite loop just where I said it would. The code you ran has to be different.

[weaknessforcats]

The code you posted crashes where I said it would:

for ( i = lengthOfStr - 1, j = 0 ; i >= 0 ; --i, ++j )
    {
        *( newStr + j ) = *( str + i );
    }
 
    *( newStr + j ) = '\0';
etc...
 

When i is zero, a --i occurs. This makes i a -1. Negative numbers are written in 2's complement so -1 looks like 4294967295, which is a very big positive number. This makes the loop run a few billion more times than planned. This causes str+i to try to access memory outside the program. Then the crash.